+ Win export declaration

Base/CMakeLists.txt

@@ -49,3 +49,7 @@ if(CLANG AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 9.0)
         target_link_libraries(${lib} PRIVATE c++fs)
     endif()
 endif()
+
+if(WIN32)
+    target_compile_definitions(${lib} PRIVATE -DBA_BASE_BUILD_DLL)
+endif()

Base/Util/Assert.h

@@ -18,12 +18,14 @@
 #ifndef BORNAGAIN_BASE_UTIL_ASSERT_H
 #define BORNAGAIN_BASE_UTIL_ASSERT_H
 
+#include "Wrap/WinDllMacros.h"
 #include <functional>
 #include <sstream>
 #include <stdexcept>
 #include <string>
 
-extern std::function<void(std::string)> failedAssertion; // set in Assert.cpp, overriden by GUI
+// Function called upon failed assert; set in Assert.cpp, overriden by GUI.
+extern BA_BASE_API_ std::function<void(std::string)> failedAssertion;
 
 // ASSERT must be declared as a macro, not a function, in order for the error
 // message to correctly report the source line where the assertion failed.

Wrap/WinDllMacros.h

+//  ************************************************************************************************
+//
+//  BornAgain: simulate and fit reflection and scattering
+//
+//! @file      Wrap/WinDllMacros.h
+//! @brief     Defines export/import macros for global data symbols
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2015
+//! @authors   Scientific Computing Group at MLZ Garching
+//
+//  ************************************************************************************************
+
+#ifndef BORNAGAIN_WRAP_WINDLLMACROS_H
+#define BORNAGAIN_WRAP_WINDLLMACROS_H
+
+//! Macros for export/import global functions and variables (Windows only).
+//!
+//! Needed for Windows, empty for Linux and Mac.
+//!
+//! Note that classes and other non-data symbols are exported automatically thanks to
+//! the CMake variable CMAKE_WINDOWS_EXPORT_ALL_SYMBOLS.
+//!
+//! One such macro is needed for each component library that exports data sybols.
+
+#ifdef _WIN32
+
+#ifdef BA_BASE_BUILD_DLL
+#define BA_BASE_API_ __declspec(dllexport)
+#else
+#define BA_BASE_API_ __declspec(dllimport)
+#endif // BA_BASE_BUILD_DLL
+
+#else // not _WIN32
+
+#define BA_BASE_API_
+
+#endif // _WIN32
+
+#endif // BORNAGAIN_WRAP_WINDLLMACROS_H